Elastic Properties of Human in Vivo Triceps Brachii Tendon

This study aimed to determine the elastic properties of human triceps brachii (TB) tendon. The elongation of the TB tendon was directly measured in 9 healthy males using ultrasonography during ramp isometric elbow-extension up to the maximal voluntary contraction (MVC). The slope of the regression line for the relationship between the estimated muscle force and the angular rotation-corrected tendon elongation above 50%MVC was defined as stiffness. The stiffness of the TB tendon, 83±22 N/mm, was comparable with that of the gastrocnemius tendon reported previously. The relationship between the stiffness and the tendon length (TL) showed a negatively significant correlation, suggesting that the stiffness of TB tendon is influenced by its dimensions.